Amlodipine, felodipine, and isradipine in the treatment of Chinese patients with mild-to-moderate hypertension

Optimal treatment of hypertension requires the use of effective antihypertensive drugs. Calcium channel blockers are widely used in the treatment of hypertension and appear to be particularly efficacious in ethnic Chinese patients. The aim of this open-label study was to prospectively investigate the efficacy and tolerability of three dihydropyridine calcium channel blockers in sequence, using the same protocol for each. After 2 weeks of placebo treatment, 73 males and 45 females (mean age, 45 +/- 10 years; mean weight, 67 +/- 10 kg) with essential hypertension (diastolic blood pressure, 95 to 115 mm Hg) were treated with amlodipine (n = 41), felodipine (n = 38), or isradipine (n = 39) for 8 weeks, with dose titration after 4 weeks. Mean seated systolic and diastolic blood pressure decreased by 23/17, 30/17, and 20/15 mm Hg after 8 weeks of treatment with amlodipine, felodipine, and isradipine, respectively. These reductions were all statistically significant. Blood pressure was controlled (defined as diastolic pressure <90 mm Hg at the final visit or a decrease from baseline of greater than or equal to 10 mm Hg) in 85%, 74%, and 74% of patients receiving amlodipine, felodipine, and isradipine, respectively. There were no significant changes in heart rate, plasma lipid levels, or serum biochemistry markers with any of the three treatments. No serious adverse events occurred, but mild adverse effects, including headaches, flushing, tachycardia, dizziness, and edema, were reported; 1 (2%), 6 (16%), and 5 (13%) patients receiving amlodipine, felodipine, and isradipine, respectively, withdrew from the study (P < 0.05). The results of this study indicate that all three drugs are highly effective in lowering blood pressure and are well tolerated in Chinese patients with mild-to-moderate hypertension.